.header {
  width: 100%;
}
.nav {
  height: 1.01333333rem;
  margin-top: 0.02666667rem;
  font-size: 0.32rem;
  line-height: 0.37333333rem;
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
}
.nav li {
  -webkit-box-flex: 1;
      -ms-flex: 1;
          flex: 1;
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-align: center;
      -ms-flex-align: center;
          align-items: center;
  text-align: center;
  -webkit-box-pack: center;
      -ms-flex-pack: center;
          justify-content: center;
}
.nav .on {
  background: #df3434;
  color: white;
}
.up {
  width: 0;
  height: 0;
  border-width: 30px 30px 0;
  border-style: solid;
  border-color: #333 transparent transparent;
  /*灰 透明 透明 */
  margin: 40px auto;
  position: relative;
}
